FCO DEMPR-R001, Shorted coax cable, self-test disabled

This Field Change Order (FCO DEMPR-R001) mandates the upgrade of all DEMPR-AA and DEMPR-AB units to a minimum Revision "C1" to address two critical issues: network performance dropping to zero due to a shorted coax cable on any port, and a disabled self-test feature requiring manual jumper removal.

The FCO details a rework procedure, requiring the replacement of existing Revision "B1" DEMPRs (especially those from the Thinwire Interim Revenue Ship (TIRS) program) with Revision "C1" or higher units. The installation process involves verifying the new unit, carefully removing the old DEMPR and its connections, installing the new unit, reconnecting all cabling, running self-test diagnostics, and finally verifying proper network operation. It also emphasizes replacing the old installation guide (EK-DEMPR-IN) with the new one (EK-DEMPR-UG-001) which is compatible with "C1" and later revisions.

A significant portion of the document provides detailed guidelines and diagrams for reconfiguring specific older TIRS network setups (Configurations #1, #2, and #3) to a standard configuration upon upgrading to a "C1" DEMPR. These reconfigurations often involve removing redundant components like DEBETs, DESTAs, or specific coaxial cable segments, and in some cases, replacing H4000-AA transceivers with H4000-BA for proper heartbeat functionality. The FCO clarifies that any network re-configurations are for informational purposes only and are not covered or charged as part of this FCO. The document concludes with LARS (Logistics and Administration Reporting System) information for tracking the change across different regions.